Free standing lighted advertising signs have recently become of common use. Such signs consist generally of a plurality of free standing letter elements or of a unitary free standing composite sign consisting of several letters, or other characters, or of a trademark representation, or the like, which are mounted on a specially provided supporting structure such as pillars or a tower, or which are attached to the front of a building such as a department store, grocery store, gasoline station or the like.
Such free standing advertising sign structures are made generally of a single-piece relatively shallow open shell of plastic material, preferably translucent, either colorless of of an appropriate color, mounted on a backing panel attached to the edge of the shell open end. The surface of the backing panel disposed towards the interior of the shell often acts as a support means for a luminary such as a fluorescent light tube bent to an appropriate contour. The electrical elements for supplying electrical power to the fluorescent light tube, such as connection boxes, transformers, and the like, are also mounted on the backing panel, generally on the rear face of the panel. Means are also provided, such as brackets and the like with appropriate fasteners, for mounting the backing panel on the supporting structure.
The backing panel has a peripheral contour corresponding to the peripheral shape of the molded shell and is attached to the edge of the shell open end by means of complex and costly intermediary fastening elements. The means provided for attaching the shell to the backing panel must permit, without destroying the ornamental value of the structure, a relatively easy disassembly of the shell and the backing panel for gaining access to the interior of the shell for maintenance, repair, or replacement of the electrical equipment and luminary. Furthermore, as the advertising sign structure is generally erected on the outside in an un-sheltered location, it is subjected to all sorts of adverse weather conditions such as wind, rain, snow, high temperature, low temperature, and the like. The structure must, therefore, be substantially weatherproof, and the interior of the shell containing relatively fragile electrical equipment and luminaries must be effectively insulated from the ambient while still permitting disassembly for replacement, repair and maintenance.
In conventional advertising plastic sign structures, the connection between the sign shell and the sign backing panel is effected by providing the peripheral edge of the shell with an outwardly projecting flange inserted in a groove of a metallic moulding, such as an extruded aluminum or stainless steel moulding bent to the peripheral contour of the shell, which is used as an intermediary member for mounting the shell on its backing panel. Shaping, bending and fastening such a metallic moulding around the periphery of the shell is a complicated, lengthy and tedious task requiring considerable skill on the part of the person effecting such an operation, especially when it is effected on shells representing individual letters of the alphabet, some of which are rather complex and may require sharp bends in the moulding which are not easily effected without providing cuts in the moulding material such as notches and the like, in view of the fact that the moulding strips are generally F-shaped, or the like, in cross section. Furthermore, in order to provide a weatherproof assembly of the shell and the backing panel, a multiplicity of gasket strips are required, such as for example one gasket strip between the shell flange surface and a surface of the moulding groove in which the flange is inserted and a gasket strip between the moulding surface and the edge surface of the backing panel at the location where the moulding is fastened to the backing panel.
In addition, it is often desirable to hide from sight the normally apparent rear surface of the backing panel and to shelter, in addition to hiding, the electrical equipment, brackets and the like fastened to the rear surface of the backing panel. Consequently, the metallic moulding is often made of a substantially wide strip such as to project a certain distance beyond the backing panel, preferably extending all the way to the supporting structure, such as to shield from view and from the weather, the electrical boxes, transformers, and mounting brackets of the sign structure. Using such a wide strip obviously complicates the problem involved in shaping, bending and fastening the strip about the periphery of the sign shell.
Another problem resulting from the use of metallic mouldings, especially when they are made of aluminum extrusions, is the relatively rapid deterioration of the surface finish due to oxidation and corrosion, and the poor surface adherence of most paint compositions to such metallic surfaces, particularly aluminum surfaces. In addition, the assembly of a plastic shell, backing panel and peripheral moulding is subject to considerable deterioration of the joints and sealed surfaces resulting from the collection of water and subsequent freezing and thawing of such water, and from continuous motion and flexing of the elements due to climatic and ambient temperature changes.
The present invention, by providing a deep drawn plastic shell having side faces or walls integrally shaped in two portions, one portion forming the side of the sign itself, and the other portion defining a skirt projecting beyond the backing panel, and by providing a step portion in the form of a contoured flange outwardly laterally projecting in a single plane and integrally formed with the side face and skirt portion of the shell, remedies the disadvantages of advertising sign structures according to the prior art. The assembly of the shell and of the backing panel of the invention is effected at the outwardly leterally extending flange portion of the shell. A simple strip gasket is used between the flange portion surface and the marginal surface of the backing panel, by being sandwiched therebetween and placed under compression, and the fastening of the shell onto the backing panel is effected by means of conventional fasteners such as screws and the like driven either through the laterally projecting flange portion of the shell or through the wall of the skirt portion proximate the ridge defined at the connection between said skirt portion and flange portion.
The skirt portion is not subject to surface corrosion and deterioration as is the case for metallic mouldings.
In addition, the skirt portion being an integral and continuous extension of the shell structure and sign surface can be painted, if so desired, either externally or internally to simulate a metallic moulding, or for any other desired esthetic effect. The paint may be chemically compounded such as to become part of the plastic surface with the result that the painted surface is not subject to the general deterioration which occurs on metallic strips. The range of color choice is substantially greater than the range of colors generally available for painting metal surfaces.